Ewan Lamont wrote:
I've just lost nearly fifteen years of Numbers for some reason...
My Desktop was untidy, so I created a new folder and put everything on my desktop in it including the last two years of Numbers data....
I inadvertently deleted the Desktop folder.
You are condemning Numbers for not being secure when the problem was you deleted your own file? That is the definition of user error. I agree that having everything accessible from all your devices makes it awfully easy to inadvertently delete things from "everywhere" when you thought you were just clearing things off your phone, for instance. But, in the case you described above, you created the file on your computer, you moved the file into a folder on your computer's desktop, and then you deleted the folder from your computer's desktop.
You did not mention if you emptied the trash. Maybe it is still in the trash and you can put it back on your desktop.
One thing to note in all this is that OS X is smart enough to track files when you move them around. After moving the file, the reason you were still able to open it "from the dock and iCloud" without getting a "file missing" error is that OS X tracks where you moved it. In the past, you would have had to track it down yourself, cursing all the while that you don't remember where you put it and why doesn't the computer keep track of it.
Also, backups are a real and necessary thing. You should be making frequent backups of your files. For critical files, I make copies and save them separately (I add a date to the filename so I know when it was). I do that just in case the main file gets corrupted. For really critical files, I may "print" a PDF of them or actually print a real hard copy for my file cabinet. For irreplaceable files, I have off-site storage (in case of fire or theft) in addition to my other measures. With Numbers and Pages files I sometimes export to Excel and Word, just to have a version that is compatible with more mainstream software, just in case.